Curated Optogenetic Publication Database

Abstract: Directed migration and rapid process extension-retraction allow microglia to continuously survey the brain and efficiently identify and phagocytose apoptotic neurons. Defining how cytoskeletal regulators coordinate these behaviors could guide strategies for targeted modulation of microglial activity. To this aim, using in vivo imaging in zebrafish, we identified a mechanistic framework in which myosin II-dependent contractility governs transitions between surveillance, migratory, and phagocytic states. Building on this, we engineered an optogenetic RhoA actuator (opto-ArhGEF25) that enables reversible, spatiotemporally precise manipulation of microglial behavior in vivo. We show that patterned RhoA activation can modulate process dynamics and induce front-rear polarity that drives rapid repulsive migration away from the applied light source, overriding injury-evoked cues and preventing migration toward lesions. Together, these results establish optogenetic control of the cytoskeleton as a powerful approach to probe and ultimately modulate microglial function in the living brain.

Abstract: Protein clustering plays numerous roles in cell physiology and disease. However, protein oligomers can be difficult to detect because they are often too small to appear as puncta in conventional fluorescence microscopy. Here, we describe a fluorescent reporter strategy that detects protein clusters with high sensitivity called CluMPS (clusters magnified by phase separation). A CluMPS reporter detects and visually amplifies even small clusters of a binding partner, generating large, quantifiable fluorescence condensates. We use computational modeling and optogenetic clustering to demonstrate that CluMPS can detect small oligomers and behaves rationally according to key system parameters. CluMPS detected small aggregates of pathological proteins where the corresponding GFP fusions appeared diffuse. CluMPS also detected and tracked clusters of unmodified and tagged endogenous proteins, and orthogonal CluMPS probes could be multiplexed in cells. CluMPS provides a powerful yet straightforward approach to observe higher-order protein assembly in its native cellular context. A record of this paper's transparent peer review process is included in the supplemental information.

Abstract: Optogenetic tools respond to light through one of a small number of behaviors including allosteric changes, dimerization, clustering, or membrane translocation. Here, we describe a new class of optogenetic actuator that simultaneously clusters and translocates to the plasma membrane in response to blue light. We demonstrate that dual translocation and clustering of the BcLOV4 photoreceptor can be harnessed for novel single-component optogenetic tools, including for control of the entire family of epidermal growth factor receptor (ErbB1-4) tyrosine kinases. We further find that clustering and membrane translocation are mechanistically linked. Stronger clustering increased the magnitude of translocation and downstream signaling, increased sensitivity to light by ~threefold-to-fourfold, and decreased the expression levels needed for strong signal activation. Thus light-induced clustering of BcLOV4 provides a strategy to generate a new class of optogenetic tools and to enhance existing ones.